Hydro power from energy for rural development NAS, Washington dc : Selected texts

Abstract

The water turbine differs from the waterwheel in that there is a contrived steady now of water through passages created by the turbine blades or buckets. The blades are so designed that water enters the passages smoothly and leaves with minimum velocity and energy, having transmitted most of its available kinetic energy to the rotor. There are three well established classes of turbines generally classified according to the names of their developers and promoters. They are, in chronological order of their appearance: Francis (reaction, full admission); Pelton (impulse, partial admission); Propeller (reaction. full admission) Nager (fixed propeller blades) and Kaplan (variable pitch propeller). Each class dominates a range of heads and speeds, and each has a unique form of runner or rotor.